Abstract:

【Objective】 This paper researched on nutrient budget and its effects on soil nutrient status in typical greenhouse system in China to provide a basis for raising the utilization rate of fertilizers and maintaining the sustainable development of agriculture in greenhouse. 【Method】 By investigating the management of 18 representative greenhouses in Shouguang, Shandong province and analyzing both the greenhouse and open field soil samples, the soil nutrient budget and the trend of nutrient accumulation and translocation in soils were studied. 【Result】 Under greenhouse cultivation,the average annual input amounts of N, P2O5 and K2O were, respectively, 4 088 kg?hm-2, 3 655 kg?hm-2, and 3 437 kg?hm-2 and 63%, 61%, and 66% of the total input amount of N, P2O5 and K2O were provided by chemical fertilizers which were the main source of soil nutrient. In greenhouse system, the utilization rate of N,P2O5, and K2O were only 24%, 8%, and 46% and the input ratio of N,P2O5, and K2O (1﹕0.9﹕0.8) was quite different from the uptake ratio (1﹕0.3﹕1.4) , thus it caused an overplus of N,P2O5, and K2O in soil and the theoretical surplus were 3 214 kg?hm-2, 3 401 kg?hm-2, and 2 322 kg?hm-2, respectively. In the greenhouse soil, the content of organic matter, total nitrogen, nitrate nitrogen, available phosphorus and available potassium were all increased and their maximum values were observed in the topsoil (0-20 cm) , with an average value being 1.4 times, 1.9 times, 21.2 times, 5.4 times, and 3.7 times than that of the open field soil, respectively. Greenhouse soils displayed apparent phenomena of nutrients leaching downwards to the bottom soil, especially NO3-, which would cause a potential risk to the quality of groundwater in the area. 【Conclusion】 Under greenhouse cultivation, it is necessary to apply more organic manure and provide nutrients according to the crop requirements and soil nutrient supplying ability as it could not only produce high crop yield,but also beneficial to balance the soil nutrient and improve the utilization rate of fertilizers, then there will be no significant surplus of nutrients which may emit or leach out of soil into environment.

Key words: greenhouse system, fertilization, nutrients budget, soil nutrient status